Turbocharger assembly

ABSTRACT

A compressor assembly can include a shaft sleeve that includes a bore that extends between a first end and a second end and an outer shoulder; a shaft received by the bore of the shaft sleeve where the shaft includes a compressor end; a compressor wheel disposed on the shaft; and a thrust collar disposed on the shaft and seated between the outer shoulder of the shaft sleeve and the compressor wheel where the thrust collar includes a stem portion and a cap portion that includes a sacrificial portion.

TECHNICAL FIELD

Subject matter disclosed herein relates generally to shaft assembliesfor compressor wheels and for turbine wheels for internal combustionengines.

BACKGROUND

A turbocharger can include a rotating group that includes a turbinewheel and a compressor wheel that are connected to one another by ashaft. For example, a turbine wheel can be welded or otherwise connectedto a shaft to form a shaft and wheel assembly (SWA) and a compressorwheel can be fit to the free end of the shaft. An electric compressorcan include one or more compressor wheels that are connected to a shaftor shafts that can be driven by an electric motor. As an example, ashaft that is attached to one or more bladed wheels may be supported byone or more bearings disposed in a bearing housing, which may form acenter housing rotating assembly (CHRA). During operation of aturbocharger or an electric compressor, depending on factors such assize of various components, a shaft may be expected to rotate at speedsin excess of 200,000 rpm. To ensure proper rotordynamic performance, arotating group should be well balanced and well supported over a widerange of conditions (e.g., operational, temperature, pressure, etc.).

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the various methods, devices,assemblies, systems, arrangements, etc., described herein, andequivalents thereof, may be had by reference to the following detaileddescription when taken in conjunction with examples shown in theaccompanying drawings where:

FIG. 1 is a diagram of a turbocharger and an internal combustion enginealong with a controller;

FIG. 2 is a perspective view of an example of a system that includeswheels and a shaft;

FIG. 3 is a cross-sectional view of a portion of the system of FIG. 2;

FIG. 4 is a perspective view of an example of an assembly of the systemof FIG. 2;

FIG. 5 is a cross-sectional view of a portion of the system of FIG. 2;

FIG. 6 is a cross-sectional view of a portion of the system of FIG. 2;

FIG. 7 is a cross-sectional view of a portion of the system of FIG. 2;

FIG. 8 is a cross-sectional view of a portion of the system of FIG. 2;

FIG. 9 is a cross-sectional view of portions of the system of FIG. 2;

FIG. 10 is a series of views of an example of a thrust collar;

FIG. 11 is a perspective view of an example of the thrust collar of FIG.10 that includes a balance cut;

FIG. 12 is a series of views of an example of a collar;

FIG. 13 is a perspective view of an example of the collar of FIG. 12that includes a balance cut;

FIG. 14 is a cross-sectional view of a portion of a turbine side of asystem;

FIG. 15 is a series of views of examples of locating components; and

FIG. 16 is a series of views of examples of locating components.

DETAILED DESCRIPTION

Below, an example of a turbocharged engine system is described followedby various examples of components, assemblies, methods, etc.

Turbochargers are frequently utilized to increase output of an internalcombustion engine. Referring to FIG. 1, as an example, a system 100 caninclude an internal combustion engine 110 and a turbocharger 120. Asshown in FIG. 1, the system 100 may be part of a vehicle 101 where thesystem 100 is disposed in an engine compartment and connected to anexhaust conduit 103 that directs exhaust to an exhaust outlet 109, forexample, located behind a passenger compartment 105. In the example ofFIG. 1, a treatment unit 107 may be provided to treat exhaust (e.g., toreduce emissions via catalytic conversion of molecules, etc.).

As shown in FIG. 1, the internal combustion engine 110 includes anengine block 118 housing one or more combustion chambers thatoperatively drive a shaft 112 (e.g., via pistons) as well as an intakeport 114 that provides a flow path for air to the engine block 118 andan exhaust port 116 that provides a flow path for exhaust from theengine block 118.

The turbocharger 120 can act to extract energy from the exhaust and toprovide energy to intake air, which may be combined with fuel to formcombustion gas. As shown in FIG. 1, the turbocharger 120 includes an airinlet 134, a shaft 122, a compressor housing assembly 124 for acompressor wheel 125, a turbine housing assembly 126 for a turbine wheel127, another housing assembly 128 and an exhaust outlet 136. The housingassembly 128 may be referred to as a center housing assembly as it isdisposed between the compressor housing assembly 124 and the turbinehousing assembly 126.

In FIG. 1, the shaft 122 may be a shaft assembly that includes a varietyof components (e.g., consider a shaft and wheel assembly (SWA) where theturbine wheel 127 is welded to the shaft 122, etc.). As an example, theshaft 122 may be rotatably supported by a bearing system (e.g., journalbearing(s), rolling element bearing(s), etc.) disposed in the housingassembly 128 (e.g., in a bore defined by one or more bore walls) suchthat rotation of the turbine wheel 127 causes rotation of the compressorwheel 125 (e.g., as rotatably coupled by the shaft 122). As an example acenter housing rotating assembly (CHRA) can include the compressor wheel125, the turbine wheel 127, the shaft 122, the housing assembly 128 andvarious other components (e.g., a compressor side plate disposed at anaxial location between the compressor wheel 125 and the housing assembly128).

In the example of FIG. 1, a variable geometry assembly 129 is shown asbeing, in part, disposed between the housing assembly 128 and thehousing assembly 126. Such a variable geometry assembly may includevanes or other components to vary geometry of passages that lead to aturbine wheel space in the turbine housing assembly 126. As an example,a variable geometry compressor assembly may be provided.

In the example of FIG. 1, a wastegate valve (or simply wastegate) 135 ispositioned proximate to an exhaust inlet of the turbine housing assembly126. The wastegate valve 135 can be controlled to allow at least someexhaust from the exhaust port 116 to bypass the turbine wheel 127.Various wastegates, wastegate components, etc., may be applied to aconventional fixed nozzle turbine, a fixed-vaned nozzle turbine, avariable nozzle turbine, a twin scroll turbocharger, etc. As an example,a wastegate may be an internal wastegate (e.g., at least partiallyinternal to a turbine housing). As an example, a wastegate may be anexternal wastegate (e.g., operatively coupled to a conduit in fluidcommunication with a turbine housing).

In the example of FIG. 1, an exhaust gas recirculation (EGR) conduit 115is also shown, which may be provided, optionally with one or more valves117, for example, to allow exhaust to flow to a position upstream thecompressor wheel 125.

FIG. 1 also shows an example arrangement 150 for flow of exhaust to anexhaust turbine housing assembly 152 and another example arrangement 170for flow of exhaust to an exhaust turbine housing assembly 172. In thearrangement 150, a cylinder head 154 includes passages 156 within todirect exhaust from cylinders to the turbine housing assembly 152 whilein the arrangement 170, a manifold 176 provides for mounting of theturbine housing assembly 172, for example, without any separate,intermediate length of exhaust piping. In the example arrangements 150and 170, the turbine housing assemblies 152 and 172 may be configuredfor use with a wastegate, variable geometry assembly, etc.

In FIG. 1, an example of a controller 190 is shown as including one ormore processors 192, memory 194 and one or more interfaces 196. Such acontroller may include circuitry such as circuitry of an engine controlunit (ECU). As described herein, various methods or techniques mayoptionally be implemented in conjunction with a controller, for example,through control logic. Control logic may depend on one or more engineoperating conditions (e.g., turbo rpm, engine rpm, temperature, load,lubricant, cooling, etc.). For example, sensors may transmit informationto the controller 190 via the one or more interfaces 196. Control logicmay rely on such information and, in turn, the controller 190 may outputcontrol signals to control engine operation. The controller 190 may beconfigured to control lubricant flow, temperature, a variable geometryassembly (e.g., variable geometry compressor or turbine), a wastegate(e.g., via an actuator), an electric motor, or one or more othercomponents associated with an engine, a turbocharger (or turbochargers),etc. As an example, the turbocharger 120 may include one or moreactuators and/or one or more sensors 198 that may be, for example,coupled to an interface or interfaces 196 of the controller 190. As anexample, the wastegate 135 may be controlled by a controller thatincludes an actuator responsive to an electrical signal, a pressuresignal, etc. As an example, an actuator for a wastegate may be amechanical actuator, for example, that may operate without a need forelectrical power (e.g., consider a mechanical actuator configured torespond to a pressure signal supplied via a conduit).

FIG. 2 shows an example of a turbocharger system 200 that includes acompressor assembly 240, a turbine assembly 260 that includes a turbinewheel 270 and a center housing 280 that is disposed between thecompressor assembly 240 and the turbine assembly 260. In the example ofFIG. 2, the center housing 280 can be an electric motor housing. In theexample of FIG. 2, a compressor inlet 201 and a compressor outlet 203are shown as well as a turbine inlet 205 and a turbine outlet 207.Further, an electric motor can be a three phase electric motor where athree phase connector 208 can be utilized to electrically connect theelectric motor to a three phase power supply, which may be controlledvia three phase electric motor control circuitry, which may be part of acomputerized control system of a vehicle (e.g., an engine control unit,etc.). As an example, power may be supplied via one or more sources. Asan example, a source can be a stored power source (e.g., one or morebatteries) or a source can be a generator or alternator source that maybe driven by an internal combustion engine (e.g., an engine that canproduce exhaust gas that can be directed to the turbine inlet 205).

FIG. 3 shows a cross-sectional view of a portion of the system 200 wherethe system 200 includes an electric motor assembly 300, a shaft 400, acompressor side bearing assembly 500 and a turbine side bearing assembly700. FIG. 3 also shows a compressor wheel 250 operatively coupled to theshaft 400, a nut 258 operatively coupled to the shaft 400 at orproximate to a compressor end 402 of the shaft 400, a compressor sideplate 242 (e.g., a backplate), a turbine side plate 262, the turbinewheel 270 that defines a turbine end 404 of the shaft 400 (e.g., as ashaft and turbine wheel assembly (SWA)), a compressor side cartridgehousing 290, an electric motor rotor 310 and an electric motor stator320.

As an example, an electric motor assembly may include a rotor that is amoving component of an electromagnetic portion that functions as anelectric motor, an electric generator and/or an electric alternator.Rotation of a rotor can be due to interaction between windings andmagnetic fields that produce a torque around a rotor's longitudinal,rotational axis. As an example, the system 200 can optionally operate asan electric generator and/or as an electric alternator. As an example,exhaust gas may be utilized to generate electricity. As an example, theelectric motor assembly 300 may optionally be utilized to apply force toa rotor that may act to resist rotation of the rotor. As an example,such an approach may act to limit boost provided by a compressor wheel.As an example, a system may be a supercharger system that includes anelectric motor and a compressor wheel.

In the example of FIG. 3, electrical power may be supplied to theelectric motor assembly 300 such that the electric motor rotor 310rotates about an axis of the shaft 400 with respect to the electricmotor stator 320. In such an example, rotation of the shaft 400 canrotate the compressor wheel 250, which may be utilized to compress air,optionally air mixed with fuel and/or exhaust.

FIG. 4 shows a perspective view of a portion of the system 200 thatincludes the electric motor rotor 310, a compressor side bearingcartridge 610 and a turbine side bearing cartridge 810. As shown, asleeve 450 extends from a compressor side to the turbine side. Thecartridge 610 includes opposing ends 612 and 614 where a recess 613 canbe utilized to azimuthally locate and/or limit rotation of the cartridge610 and the cartridge 810 includes opposing ends 812 and 814 where arecess 813 can be utilized to azimuthally locate and/or limit rotationof the cartridge 810.

In the example of FIG. 4, the recess 613 is open to one side whereas therecess 813 is closed. In such an example, the recess 813 may act toaxially locate and/or limit axial movement of the cartridge 810 and, forexample, one or more other components that may be operatively coupled tothe cartridge 810.

In the example of FIG. 4, a lock nut 650 is threaded onto the sleeve 450via mating of internal threads of the lock nut 650 (e.g., ID threads)and external threads of the sleeve 450 (e.g., OD threads). The lock nut650 can be secured via one or more set screws 661-1 and 661-2. Forexample, the lock nut 650 can be threaded onto the sleeve 450 to adesired position and/or a desired torque and then at least one of theset screws 661-1 and 661-2 can be rotated about its axis to contact thesleeve 450 with force sufficient to prevent rotation of the lock nut 650with respect to the sleeve 450. As an example, the lock nut 650 caninclude features that allow for interaction with a tool that can rotatethe lock nut 650. As an example, such features may be axial slots thatmay also be passages that can allow for flow of lubricant (e.g., from abearing assembly toward a thrust collar).

FIG. 5 shows a cross-sectional view of a portion of the system 200 wherevarious compressor side components can be seen. In FIG. 5, thecompressor wheel 250 is mounted onto the shaft 400 where a thrust collar540 is disposed at least in part axially between the compressor wheel250 and at least a portion of the sleeve 450. In such an example, thecompressor wheel 250 can be secured onto the shaft 400 via tightening ofthe nut 258 (e.g., a shaft nut) such that an axial load is carried bythe thrust collar 540 and the sleeve 450. As shown, the axial load isnot carried by the lock nut 650, which is threaded onto the sleeve 450.

More particularly, in the example of FIG. 5, an axial face surface 254of the compressor wheel 250 contacts an axial face surface 542 of thethrust collar 540 and an opposing axial face surface 544 of the thrustcollar 540 contacts an axial face surface 453 of the sleeve 450. Asshow, an axial clearance (e.g., an axial gap) exists between the thrustcollar 540 and an axial face surface 652 of the lock nut 650. In theexample of FIG. 5, an axial clearance (e.g., an axial gap) also existsbetween an end 259 of the compressor wheel 250 and an end 452 of thesleeve 450. Thus, in such an example, the compressor wheel 250 does notdirectly contact the sleeve 450, rather the compressor wheel 250contacts the thrust collar 540, which contacts the sleeve 450.

As shown, the plate 242 includes a bore and the thrust collar 540 isdisposed at least in part in the bore where, for example, seal memberssuch as piston rings, may be set in annular grooves of the thrust collar540 to hinder flow of fluid from a compressor side to a center housingside of the plate 242 and/or vice versa. In the example of FIG. 5, thecompressor wheel 250 rotates with the shaft 400, the sleeve 450, thethrust collar 540 and the lock nut 650.

FIG. 5 shows the cartridge 610 as being set in a bore 291 of thecompressor side cartridge housing 290 where, for example, one or moreseal members 663 and 665 (e.g., O-rings, which may be elastomeric) maybe received in one or more annular grooves to form a seal between anouter surface of the cartridge 610 and an inner surface of the bore 291of the compressor side cartridge housing 290. As shown, the cartridge610 includes opposing ends 612 and 614, noting that a portion of thecartridge 610 extends axially inwardly from the end 614 (see, e.g.,cross-section view of FIG. 3).

FIG. 5 also shows a locating plate 910 that includes a surface 914 thatabuts an end surface 292 of the compressor side cartridge housing 290.As an example, the locating plate 910 can be bolted or otherwise securedto the compressor side cartridge housing 290. In such an example, aportion of the locating plate 910 is received by the recess 613 of thecartridge 610 such that rotation of the cartridge 610 is limited (e.g.,azimuthal locating). In such an example, some radial movement of thecartridge 610 in the bore 291 may occur, for example, via an extentallowable by the seal members 663 and 665 (e.g., elastomeric O-rings).As an example, such seal members may define a lubricant space betweenthe cartridge 610 and the compressor side cartridge housing 290 suchthat one or more lubricant squeeze films are formed. Such films may actto damp vibrations and/or to transfer heat energy (e.g., via flow oflubricant).

As shown in FIG. 5, the cartridge 610 includes a bore 611 that receivesvarious bearing components, including components of a first bearingassembly 620 and components of a second bearing assembly 630. As shown,the bearing assembly 620 includes an inner race 621, an outer race 625and rolling elements 629 disposed between the inner race 621 and theouter race 625. As shown, the bearing assembly 630 includes an innerrace 631, an outer race 635 and rolling elements 639 disposed betweenthe inner race 631 and the outer race 635.

Components disposed between the first bearing assembly 620 and thesecond bearing assembly 630 can include an outer ring 641 and an innerring 645 where the outer ring 641 includes one or more lubricantpassages 643. FIG. 5 shows an example of the outer ring 641 as includinga lubricant passage 643 as an inlet lubricant passage (e.g., lubricantopening) and as including one or more lower lubricant passages (e.g.,lubricant openings). The outer ring 641 also shows a notch that canreceive a locating pin, which may limit rotation of the outer ring 641about the z-axis (e.g., to assure proper alignment of lubricantfeatures). The cartridge 610 can include one or more passages 615 thatcan be in fluid communication with one or more passages 295 of thecompressor side cartridge housing 290 such that lubricant can be fed tothe first bearing assembly 620 and the second bearing assembly 630(e.g., via the outer ring 641).

In the example of FIG. 5, the lock nut 650 may be considered to be aninner lock nut that axially locates and/or axially loads the inner races621 and 631 with the inner ring 645 therebetween. In the example of FIG.5, an outer lock nut 670 includes a bore 671 and outer threads that matewith inner threads of the bore 611 of the cartridge 610. The outer locknut 670 may be used to axially locate and/or to axially load the outerraces 625 and 635 with the outer ring 641 therebetween. As shown, thecartridge 610 includes an axial face surface 618 within the bore 611where a surface 638 of the outer race 635 can abut the axial facesurface 618, which may be an axial stop surface that axially locates theouter race 635.

As to axial stacking, the surface 638 of the outer race 635 abuts theaxial face surface 618 of the cartridge 610, a surface 644 of the outerring 641 abuts a surface 636 of the outer race 635, a surface 628 of theouter race 625 abuts a surface 642 of the outer ring 641 and a surface674 of the outer lock nut 670 abuts a surface 626 of the outer race 625.

As an example, the lock nut 650 may be adjusted to an axial position,optionally according to an amount of torque, to axially locate and/or toaxially load the inner races 621 and 631 and the inner ring 645 wherethe inner race 631 includes a surface 634 that abuts an axial facesurface 456 of the sleeve 450 (e.g., an annular shoulder of the sleeve450).

As to axial stacking, the surface 634 of the inner race 631 abuts theaxial face surface 457 of the sleeve 450, a surface 648 of the innerring 645 abuts a surface 632 of the inner race 631, a surface 624 of theinner race 621 abuts a surface 646 of the inner ring 645 and the surface654 of the lock nut 650 abuts a surface 622 of the inner race 621.

In the example of FIG. 5, the sleeve 450, the lock nut 650, the innerrace 621, the inner ring 645 and the inner race 631 rotate with theshaft 400 and the compressor wheel 250.

In the example of FIG. 5, the inner races 621 and 631 and the inner ring645 can be independent of a load applied to the compressor wheel 250 andthe thrust collar 540. In such an example, where an inner race may berelatively thin or otherwise deformable under an applied load, as may betransferred from a tightened compressor wheel, the inner race is notsubjected to such an applied load. Such an approach can allow forutilization of a type of bearing assembly that is independent of loadapplied axially to a compressor wheel (e.g., load applied by thecompressor wheel 250 to the thrust collar 540 and to the shaft sleeve450).

As an example, a set of angular contact ball bearing assemblies can beconfigured in one or more types of configurations. For example, consideran O-type configuration, an X-type configuration and a T-typeconfiguration. As an example, bearing assemblies may be installed inpairs and configured according to how their outer races are oriented.For example, consider a back to back configuration known as an O-typeconfiguration, a face to face configuration known as an X-typeconfiguration, and a series configuration known as a T-configuration orT-type configuration. In FIG. 5, the bearing assemblies 620 and 630 areshown in an X-type configuration where the outer ring 641 is disposedaxially between the outer race 625 and the outer race 635, which haveradially thicker portions that extend to the surfaces 626 and 638,respectively. In such an example, the contact angle for the bearingassembly 620 is oriented from the ball 629 toward the surface 626 andthe contact angle for the bearing assembly 630 is oriented from the ball639 toward the surface 638; thus, lines drawn along these two contactangles form an “X” pattern.

As an example, bearing assemblies may be oriented in an O-typeconfiguration. For example, the bearing assemblies 620 and 630 may beoriented in a back to back configuration with the inner ring 645disposed between the inner races 621 and 631. In such an example, theradially thicker portions of the inner races 621 and 631 at surfaces 624and 632 may bear a load, which may be applied by tightening the lock nut650 on the shaft sleeve 450 (e.g., to a desired torque, etc.).

In the example of FIG. 5, the lock nut 650 is adjusted to be in an axialposition that allows the lock nut 650 to axially limit movement of theinner races 621 and 631 and the inner ring 645. The lock nut 650 can beadjusted via rotation as threads having a thread pitch can causerotation of the lock nut 650 with respect to threads having a threadpitch of the shaft sleeve 450 to translate the lock nut 650 axially. Thelock nut 650 can hold the inner races 621 and 631 and the inner ring 645to prevent axial displacement of the bearing assemblies 620 and 630. Inan X-type configuration, the outer lock nut 670 may be rotated via matedthreads to translate the outer lock nut 670 axially away from the thrustcollar 540 such that a load may be applied to the outer races 625 and635 and the outer ring 643.

As explained above, the bearing assemblies 620 and 630, the lock nut 650and the outer lock nut 670 may be in one or more configurations where alock nut can axially locate and/or apply an axial load. In suchexamples, such an axial load can be independent of an axial loadassociated with tightening a compressor wheel. In the example of FIG. 5,the inner races 621 and 631 and the inner ring 643 are secured to rotatewith the sleeve 450 and the outer races 625 and 635 and the outer ring641 are secured to the cartridge 610, which remains relativelystationary with respect to the sleeve 450. As an example, an assemblymay include one or more springs that can be axially positioned to applya load to a portion of a bearing assembly or portions of bearingassemblies.

FIG. 6 shows a cross-sectional view of a portion of the system 200 wherevarious axial dimensions are indicated with respect to surfaces,particularly axial facing surfaces. Such surfaces include various pairedsurfaces that can be in contact and contribute to axial stack-up as tovarious components.

As shown in FIG. 6, the thrust collar 540 can be defined by an axiallength, the lock nut 650 can be defined by an axial length, the outerlock nut 670 can be defined by an axial length, the first bearingassembly 620 can be defined by an axial length or axial lengths, theouter ring 641 can be defined by an axial length, the inner ring 645 canbe defined by an axial length, the second bearing assembly 630 can bedefined by an axial length or axial lengths, etc.

As shown in FIG. 6, an axial clearance exists between the compressorwheel 250 and the sleeve 450 and an axial clearance exists between thethrust collar 540 and the lock nut 650.

As shown in FIG. 6, the axial length of the lock nut 650 can be greaterthan the axial length of the outer lock nut 670 such that the lock nut650 extends axially closer to the thrust collar 540 and such that anextension 913 of the locating plate 910 can extend radially inwardly toa radial position that is less than an outer radius of the outer locknut 670.

As shown in FIG. 6, the locating plate 910 can be in contact with thecompressor side cartridge housing 290, for example, by being attached tothe compressor side cartridge housing 290 (e.g., via one or more bolts,etc.). As mentioned, the locating plate 910 can be an anti-rotationcomponent that can limit rotation of the cartridge 610 about therotational axis of the shaft 400. In such an example, the outer races625 and 635 and the outer ring 641, as well as the outer lock nut 670,can be limited in their rotation via contact with an inner surface ofthe bore 611 of the cartridge 610 while the inner races 621 and 631 andthe inner ring 645, along with the lock nut 650, rotate with the shaft400 and the sleeve 450 (e.g., and the thrust collar 540).

FIG. 6 also shows arrows as to lubricant flow through the compressorside cartridge housing 290, through the cartridge 610 and into thepassages 643 of the outer ring 641 such that the first bearing assembly620 and the second bearing assembly 630 can be lubricated (e.g., forlubricant and heat removal). As shown in FIG. 6, the bore 671 of theouter lock nut 670 defines a clearance with respect to the lock nut 650such that lubricant may flow from spaces associated with the firstbearing assembly 620 and the second bearing assembly 630 to a space thatis in fluid communication with a drain (e.g., a lubricant outlet) thatcan be, for example, a cross-bore, etc. in the compressor side cartridgehousing 290 (see, e.g., FIG. 2).

FIG. 7 shows a cross-sectional view of a portion of the system 200 wherevarious turbine side components can be seen. In FIG. 7, the turbinewheel 270 is connected to a hub portion 430 of the shaft 400 to form ashaft and wheel assembly (SWA). As an example, the turbine wheel 270 canbe welded to the hub portion 430 of the shaft 400. As shown, the hubportion 430 of the shaft 400 includes annular grooves that can receiveone or more seal members 869 such as, for example, one or more pistonrings. The turbine side plate 262 includes a bore through which theshaft 400 can be inserted such that the one or more seal members 869 cancontact a bore surface to hinder flow of fluid from a turbine side to abearing side or vice versa. For example, lubricant flow may be hinderedfrom the bearing side to the turbine side and exhaust flow may behindered from the turbine side to the bearing side. As shown in FIG. 7,the turbine side plate 262 includes an annular groove that can receive aseal member 867 such as, for example, an O-ring that can form a sealwith a surface of the center housing 280.

As shown in FIG. 7, the sleeve 450 includes an axial face surface 454that seats against an axial face surface 432 of the hub portion 430 ofthe shaft 400. In such an example, the sleeve 450 is axially supportedby the shaft 400 such that force applied to the compressor wheel 250,for example, via tightening of the nut 258 on the shaft 400, appliesforce to the thrust collar 540, which applies force to the sleeve 450.

In the example of FIG. 7, inner races 821 and 831 of a first bearingassembly 820 and a second bearing assembly 830, respectively, and aninner ring 845 can be independent of a load applied to the compressorwheel 250 and the thrust collar 540, which can be transferred via theshaft sleeve 450 to the axial face surface 432 of the hub portion 430 ofthe shaft 400. In such an example, where an inner race may be relativelythin or otherwise deformable under an applied load, as may betransferred from a tightened compressor wheel, the inner race is notsubjected to such an applied load. Such an approach can allow forutilization of a type of bearing assembly that is independent of loadapplied axially to a compressor wheel (e.g., load applied by thecompressor wheel 250 to the thrust collar 540 and to the shaft sleeve450).

As mentioned, a set of angular contact ball bearing assemblies can beconfigured in one or more types of configurations. For example, consideran O-type configuration, an X-type configuration and a T-typeconfiguration. As mentioned, bearing assemblies may be installed inpairs and configured according to how their outer races are oriented(e.g., a back to back configuration known as an O-type configuration, aface to face configuration known as an X-type configuration, and aseries configuration known as a T-configuration or T-typeconfiguration). In FIG. 7, the bearing assemblies 820 and 830 are shownin an X-type configuration where the outer ring 841 is disposed axiallybetween an outer race 825 of the bearing assembly 820 and an outer race835 of the bearing assembly 830, which have radially thicker portionsthat extend to surfaces 828 and 836, respectively. In such an example,the contact angle for the bearing assembly 820 is oriented from a ball829 (e.g., rolling element) toward the surface 828 and the contact anglefor the bearing assembly 830 is oriented from a ball 839 (e.g., rollingelement) toward the surface 836; thus, lines drawn along these twocontact angles form an “X” pattern.

As an example, bearing assemblies may be oriented in an O-typeconfiguration. For example, the bearing assemblies 820 and 830 may beoriented in a back to back configuration with the inner ring 845disposed between the inner races 821 and 831. In such an example, theradially thicker portions of the inner races 821 and 831 at surfaces 822and 834 may bear a load, which may be applied by tightening the lock nut850 on the shaft sleeve 450 (e.g., to a desired torque, etc.).

In the example of FIG. 7, the lock nut 850 is adjusted to be in an axialposition that allows the lock nut 850 to axially limit movement of theinner races 821 and 831 and the inner ring 845. The lock nut 850 can beadjusted via rotation as threads having a thread pitch can causerotation of the lock nut 850 with respect to threads having a threadpitch of the shaft sleeve 450 to translate the lock nut 850 axially. Thelock nut 850 can hold the inner races 821 and 831 and the inner ring 845to prevent axial displacement of the bearing assemblies 820 and 830. Inan X-type configuration, the outer lock nut 870 may be rotated via matedthreads to translate the outer lock nut 870 axially away from the hubportion 430 such that a load may be applied to the outer races 825 and835 and the outer ring 843.

As explained above, the bearing assemblies 820 and 830, the lock nut 850and the outer lock nut 870 may be in one or more configurations where alock nut can axially locate and/or apply an axial load. In suchexamples, such an axial load can be independent of an axial loadassociated with tightening a compressor wheel. As an example, anassembly may include one or more springs that can be axially positionedto apply a load to a portion of a bearing assembly or portions ofbearing assemblies.

As shown in FIG. 7, at the turbine side, the first bearing assembly 820and the second bearing assembly 830 also include the inner races 821 and831, respectively, which are seated with respect to the shaft sleeve 450and axially located via the lock nut 850. As shown in FIG. 7, an axialclearance (e.g., an axial gap) exists between the lock nut 850 and thehub portion 430 of the shaft 400. Specifically, the axial clearanceexists between a surface 854 of the lock nut 850 and the hub portion 430of the shaft 400 (e.g., the surface 432).

In the example of FIG. 7, the lock nut 850 is threaded onto the sleeve450 via mating of internal threads of the lock nut 850 (e.g., IDthreads) and external threads of the sleeve 450 (e.g., OD threads). Thelock nut 850 can be secured via a set screw 861 or set screws. Forexample, the lock nut 850 can be threaded onto the sleeve 450 to adesired position and/or a desired torque and then the set screw 861 canbe rotated about its axis to contact the sleeve 450 with forcesufficient to prevent rotation of the lock nut 850 with respect to thesleeve 450.

As an example, a system can include one or more compressor side bearingassemblies that are loaded by a compressor side lock nut and one or moreturbine side bearing assemblies that are loaded by turbine side locknut. In such a system, the bearing assemblies can be loaded against asleeve where inner races of the bearing assemblies rotate with thesleeve. Further, the sleeve can include a stop surface that can seat acompressor side thrust collar and, for example, a shaft can include astop surface that can seat the sleeve. A sleeve can carry a compressorwheel load and can carry one or more independent loads as associatedwith one or more bearing assemblies. A compressor wheel load may be acompressive as applied to a sleeve and tensile as applied to a shaft. Abearing assembly load can be compressive as applied to a bearingassembly and can be tensile as applied to a sleeve.

FIG. 7 shows the cartridge 810 as being set in a bore 289 of the housing280 where, for example, one or more seal members 863 and 865 (e.g.,O-rings, which may be elastomeric) may be received in one or moreannular grooves to form a seal between an outer surface of the cartridge810 and an inner surface of the bore 289 of the compressor sidecartridge housing 290. As shown, the cartridge 810 includes opposingends 812 and 816, noting that a portion of the cartridge 810 extendsaxially inwardly from the end 816 (see, e.g., cross-section view of FIG.3) to an end 814. In such an example, some radial movement of thecartridge 810 in the bore 289 may occur, for example, via an extentallowable by the seal members 863 and 865 (e.g., elastomeric O-rings).As an example, such seal members may define a lubricant space betweenthe cartridge 810 and the housing 280 such that one or more lubricantsqueeze films are formed. Such films may act to damp vibrations and/orto transfer heat energy (e.g., via flow of lubricant).

FIG. 7 also shows a locating plate 930 that includes a surface 932 thatabuts an end surface 283 of the housing 280. As an example, the locatingplate 930 can be bolted or otherwise secured to the housing 280. In suchan example, an extension 933 of the locating plate 930 is received bythe recess 813 of the cartridge 810 such that rotation of the cartridge810 is limited azimuthally (e.g., azimuthal locating) and such that thecartridge 810 is limited axially (e.g., axial locating).

As shown in FIG. 7, the cartridge 810 includes a bore 811 that receivesvarious bearing components, including components of the first bearingassembly 820 and components of the second bearing assembly 830. Asshown, the bearing assembly 820 includes the inner race 821, an outerrace 825 and rolling elements 829 disposed between the inner race 821and the outer race 825. As shown, the bearing assembly 830 includes theinner race 831, an outer race 835 and rolling elements 839 disposedbetween the inner race 831 and the outer race 835.

Components disposed between the first bearing assembly 820 and thesecond bearing assembly 830 include the outer ring 841 and the innerring 845 where the outer ring 841 includes one or more lubricantpassages 843. FIG. 7 shows an example of the outer ring 841 as includinga lubricant passage 843 as an inlet lubricant passage (e.g., lubricantopening) and as including one or more lower lubricant passages (e.g.,lubricant openings). The outer ring 841 also shows a notch that canreceive a locating pin, which may limit rotation of the outer ring 841about the z-axis. The cartridge 810 can include one or more passages 815that can be in fluid communication with one or more passages 285 of thehousing 280 such that lubricant can be fed to the first bearing assembly820 and the second bearing assembly 830.

In the example of FIG. 7, the lock nut 850 may be considered to be aninner lock nut that can axially locate and/or axially load the innerraces 821 and 831 with the inner ring 845 therebetween. In the exampleof FIG. 7, the outer lock nut 870 includes a bore 871 and includes outerthreads that mate with inner threads of the bore 811 of the cartridge810. The outer lock nut 870 may be used to axially locate and/or axiallyload the outer races 825 and 835 with the outer ring 841 therebetween.As shown, the cartridge 810 includes an axial face surface 818 withinthe bore 811 where a surface 836 of the outer race 835 can abut theaxial face surface 818, which may be an axial stop surface that axiallylocates the outer race 835.

As to axial stacking, the surface 836 of the outer race 835 abuts theaxial face surface 818 of the cartridge 810, a surface 842 of the outerring 841 abuts the surface 838 of the outer race 835, the surface 826 ofthe outer race 825 abuts a surface 844 of the outer ring 841 and asurface 872 of the outer lock nut 870 abuts a surface 828 of the outerrace 825.

As mentioned, the lock nut 850 may be adjusted to axially locate and/oraxially load the inner races 821 and 831 and the inner ring 845 wherethe inner race 831 includes the surface 832 that abuts an axial facesurface 458 of the sleeve 450.

As to axial stacking, the surface 832 of the inner race 831 abuts theaxial face surface 458 of the sleeve 450, a surface 846 of the innerring 845 abuts the surface 834 of the inner race 831, the surface 822 ofthe inner race 821 abuts a surface 848 of the inner ring 845 and thesurface 852 of the lock nut 850 abuts a surface 824 of the inner race821.

In the example of FIG. 7, the sleeve 450, the lock nut 850, the innerrace 821, the inner ring 845 and the inner race 831 rotate with theshaft 400 and the turbine wheel 270.

In the example of FIG. 7, a load applied to bearing assemblies 820 and830 and the inner ring 845 and/or the outer ring 841 can be independentof a load applied to the sleeve 450 via tightening of the nut 258 on theshaft 400 to secure the compressor wheel 250.

FIG. 8 shows a cross-sectional view of a portion of the system 200 wherevarious axial dimensions are indicated with respect to surfaces,particularly axial facing surfaces.

As shown in FIG. 8, the lock nut 850 can be defined by an axial length,the outer lock nut 870 can be defined by an axial length, the firstbearing assembly 820 can be defined by an axial length or axial lengths,the outer ring 841 can be defined by an axial length, the inner ring 845can be defined by an axial length, the second bearing assembly 830 canbe defined by an axial length or axial lengths, etc.

As shown in FIG. 8, an axial clearance exists between the hub portion430 of the shaft 400 and the lock nut 850.

As shown in FIG. 8, the axial length of the lock nut 850 can be greaterthan the axial length of the outer lock nut 870 such that the lock nut850 extends axially closer to the hub portion 430 of the shaft 400 andsuch that an extension 933 of the locating plate 930 can extend radiallyinwardly to a radial position that is less than an outer radius of theouter lock nut 870.

As shown in FIG. 8, the locating plate 930 can be in contact with thehousing 280, for example, by being attached to the housing 280 (e.g.,via one or more bolts, etc.). As mentioned, the locating plate 930 canbe an anti-rotation component that can limit rotation of the cartridge810 about the rotational axis of the shaft 400 and/or can be ananti-translation component that can limit axial translation of thecartridge 810. In such an approach, the outer races 825 and 835 and theouter ring 841, as well as the outer lock nut 870, can be limited intheir rotation via contact with an inner surface of the bore 811 of thecartridge 810 while the inner races 821 and 831 and the inner ring 845,along with the lock nut 850, rotate with the shaft 400 and the sleeve450.

As an example, the extension 933 of the locating plate 930 may beinserted into the recess 813 of the cartridge 810 and then the cartridge810 may be drawn into the bore 289 of the housing 280 and the locatingplate 930 fixed to the housing 280 (e.g., via one or more bolts, etc.).At the compressor side of the system 200, the locating plate 910 can beattached such that its extension 913 aligns with the recess 613 of thecartridge 610. As shown in FIG. 3, the recess 613 can be open at oneside such that the locating plate 910 can be positioned with itsextension 913 aligned with the recess 613 of the cartridge 610. One ormore bolts (e.g., or other attachment components, etc.) may be utilizedto fix the locating plate 910 to the compressor side cartridge housing290, which can be fixed to the housing 280. In such an example, thecartridge 610 is located at least in part by the locating plate 910 andthe cartridge 810 is located at least in part by the locating plate 930.As an example, the locating plate 930 can axially locate the cartridge810 and thereby limit its axial movement in either of two opposing axialdirections.

FIG. 8 also shows arrows as to lubricant flow through the housing 280,through the cartridge 810 and into the passages 843 of the outer ring841 such that the first bearing assembly 820 and the second bearingassembly 830 can be lubricated (e.g., for lubricant and heat removal).As shown in FIG. 8, the bore 871 of the outer lock nut 870 defines aclearance with respect to the lock nut 850 such that lubricant may flowfrom spaces associated with the first bearing assembly 820 and thesecond bearing assembly 830 to a space that is in fluid communicationwith a drain (e.g., a lubricant outlet) that can be, for example, across-bore, etc. in the housing 280 (see, e.g., FIG. 2).

FIG. 9 shows various components of the system 200 of FIG. 2 where acompressor side bearing assembly 510 is loaded onto the sleeve 450 bytorque applied to the lock nut 650 and where a turbine side bearingassembly 710 is loaded onto the sleeve by torque applied to the lock nut850. As shown, the compressor wheel 250 applies a load on the sleeve 450via the thrust collar 540. As shown, the cartridge 610 is located by alocating plate 910 and the cartridge 810 is located by a locating plate930.

In the example of FIG. 9, the sleeve 450 and bearing assemblies 510 and710 may be considered to be a sub-assembly, along with the lock nuts 650and 850, which act to locate and load the bearing assemblies 510 and710, respectively, while the sleeve 450 can bear a load against the hubportion 430 of the shaft 400 as applied by the thrust collar 540 and thecompressor wheel 250 being in contact with the thrust collar 540 wherethe nut 258 or other mechanism may be utilized to load the compressorwheel 250 with respect to the shaft 400 and the sleeve 450.

In the example of FIG. 9, the sleeve 450 can be a single piece formed ofa metal or metal alloy that extends an axial length between opposingends 452 and 454 where the end 452 is a free end and where the end 454is in contact with the hub portion 430 of the shaft 400. As shown, theshaft 400 is received by the bore 451 of the sleeve 450 where one ormore pilot portions of the shaft 400 can be in contact with a surface ofthe sleeve 450 that defines the bore 451. The bore 451 may include oneor more diameters, one or more features, etc. For example, the bore 451can be a stepped bore. Such a stepped bore can include one or morelarger diameter portions at and/or near an end or ends and can include asmaller diameter portion over a length that is intermediate the largerdiameter portions.

FIG. 10 shows a plan view of the thrust collar 540 and a cross-sectionalview of the thrust collar 540 along a line N-N. In FIG. 10, the thrustcollar 540 is shown as including a through bore 541 that extends betweenends 542 and 544. The thrust collar 540 also includes an outer perimeter543 (e.g., at a maximum diameter or maximum radius), which includesnotches 545-1 and 545-2 that are disposed at about 180 degrees from eachother in azimuthal angle about a longitudinal axis of the thrust collar540 where such notches can be speed monitoring features. For example, aspeed sensor 1010 can detect the notches 545-1 and 545-2 where sensedinformation may be used to determine rotational speed of the shaft 400.As an example, a thrust collar can include one or more notches. Where athrust collar includes a plurality of notches, they may be located atangles that aim to balance the thrust collar where removal of materialfrom a sacrificial portion can be utilized to balance an assembly thatis a rotating assembly that includes the thrust collar.

In the example of FIG. 10, the thrust collar 540 includes a stem portion552 and a cap portion 554 where the cap portion 554 includes asacrificial portion 556, which can have, as an example, a substantiallytriangular cross-section, which may be an acute triangle (three anglesacute, less than 90 degrees) or an obtuse triangle (one obtuse angle,greater than 90 degrees and two acute angles). As an example, a largestinterior angle of a triangular shape may be a peak angle or free angle(e.g., at a free peak of a sacrificial portion).

As shown, the cap portion 554 also includes a sensor surface 558, whichis disposed at an angle to the longitudinal axis (z-axis) of the thrustcollar 540. As shown in FIG. 10, the sacrificial portion 556 is formedas an integral portion of the thrust collar 540. As an example, thethrust collar 540 may be formed at least in part by machining stockmetallic material (e.g., metal or metal alloy). The sacrificial portion556 may be formed and shaped in a manner that does not introduce anamount of stress that may give rise to failure of the thrust collar 540as it rotates, which may be at speeds of tens of thousands revolutionsper minute, which may exceed 100,000 rpm.

The sacrificial portion 556 of the thrust collar 540 can be asubstantially continuous annular portion, which may be interrupted bycontinuations of the notches 545-1 and 545-2. For example, each of thenotches 545-1 and 545-2 may span an azimuthal angle of about 10 degreessuch that the sacrificial portion 556 includes two spans each of aboutan azimuthal angle of about 175 degrees. As an example, a thrust collarmay include a number of equally spaced sacrificial portions wherematerial may be removed from one or more of the sacrificial portions aspart of a balancing process. In such an example, removal of the materialmay impart or form balance cuts. As shown in FIG. 10, the sacrificialportion 556 is disposed at or near an outermost perimeter of the thrustcollar 540 such that a mass of material removed may impart a substantialeffect on balance. The sacrificial portion 556 is positioned as toreduce structural effect on the stem portion 552, which can bear a loadassociated with tightening of a compressor wheel.

In FIG. 10, various axial dimensions and radial dimensions of the thrustcollar 540 are shown. In cross-section, the thrust collar 540 has aJ-shape (e.g., a body of revolution formed by a J-shape which may berotated 360 degrees) or a hat shape (e.g., a mushroom shape).

FIG. 10 shows a series of increasing radii r₁, r₂, r₃, r₄, r₅, r₆ andr₇. The sacrificial portion 556 can be disposed between radii r₄ and r₇(see, e.g., Δr as a base dimension of the sacrificial portion 556) wherea peak radius, r_(p), may correspond to the radius r₅. As an example,the radius r₆ may correspond to a sensor radius of the sensor surface558. FIG. 10 also shows axial dimensions z₁, z₂, z₃ and z₄ where thesacrificial portion 556 can be of an axial dimension Δz, which can beequal to a difference between z₂ and z₃. As shown in FIG. 10, the stemportion 552 has an axial length z₁ and a radius r₂ with a bore 541having a bore radius r₁ while the cap portion 554 has axial lengths ofz₄, z₃ and z₂ over radii from r₂ to r₇. The notches 545-1 and 545-2 areshown of having a radial depth of about a difference between radii r₅and r₇.

In the example of FIG. 10, the thrust collar 540 includes a r,Θ-planedefined in a cylindrical coordinate system (r, z, Θ) where the r,Θ-planeis at an axial position labeled z_(s), which demarcates the sacrificialportion 556 of the cap portion 554. As shown, the sacrificial portion556 extends in an axial direction away from the r,Θ-plane toward the end542 of the thrust collar 540, which is in an axial direction toward thecompressor wheel 250 in the system 200. Specifically, in the example ofFIG. 10, the sacrificial portion 566 of the thrust collar 540 can bepositioned as practically close as possible toward the compressor end ofthe shaft 400 for the purpose of having a greater effect on balancing ofa rotating group. As an example, a sacrificial portion can be positionedto avoid “confusing” a speed sensor (e.g., to avoid interference with aspeed sensor's ability to sense speed).

As an example, the speed sensor 1010 can be pointed at the sensorsurface 558 that is substantially perpendicular to an axis of the speedsensor 1010 (x-axis). When a metallic material is in proximity to thetip of the speed sensor 1010, a charge can build up. The notches 545-1and 545-2 in the metallic material of the thrust collar 540 can pass thetip of the speed sensor 1010 and release at least a portion of the builtup charge and circuitry operatively coupled to the speed sensor 1010 orpart of the speed sensor 1010 can thereby detect a rotation of thethrust collar 540, for example, for calculating the speed of a rotatinggroup. As to a balance cut, if a cut were made on the outer diameter(e.g., outer perimeter), the speed sensor 1010 may possibly incorrectlyread the cut as a notch and increase the count.

FIG. 10 shows a cross-sectional view of the sacrificial portion 556 asdefined in part by the radial dimension Δr, the axial dimension Δz andthe peak radius r_(p). Material of the sacrificial portion 556 may beremoved at least in part to balance a rotating group where removal ofsuch material does not interfere with the notches 545-1 and 545-2 andthe speed sensor 1010 being able to sense speed of the thrust collar 540as it rotates (e.g., to count full or fractional rotations).

The sacrificial portion 556 can include a sufficient amount of materialto allow for balancing of a rotating group of a turbocharger such asshown in the system 200 of FIG. 2. As an example, a balancing process orbalancing processes may include cutting the compressor wheel 250 and/orthe nut 258 and/or the thrust collar 540.

As shown in the example of FIG. 10, the thrust collar 540 includesannular grooves 547-1 and 547-2 that can receive seal elements such as,for example, piston rings, which as mentioned may contact the backplate242, which can be attached to the compressor side cartridge housing 290(see, e.g., FIG. 3).

Referring to FIG. 5, the thrust collar 540 may come into contact withlubricant that exits an annular space between the lock nut 650 and thecartridge 610 and/or the outer lock nut 670. During operation, suchlubricant may be driven radially outwardly along the end 544 of thethrust collar 540 and then along a surface 559 intermediate the end 544and the sensor surface 558. As the lubricant moves radially outwardly,it may be flung off of the thrust collar 540 and into a space defined inpart by the compressor side bearing cartridge housing 290 and thebackplate 242. Such an arrangement of components may hinder migration oflubricant along the stem portion 552 of the thrust collar 540 and towardthe compressor wheel 250. As an example, the perimeter 543 of the thrustcollar 540 may form an outermost limit for migration of lubricant wherelubricant is flung radially outwardly therefrom. As shown in FIG. 10,the axial dimension z₃ corresponds to the radius r₇, which can be seen,for example, in FIG. 5 as (z₃, r₇). As seen in FIG. 5, the sacrificialportion 556 can help reduce migration of lubricant between the backplate242 and the thrust collar 540.

FIG. 11 shows the thrust collar 540 as having material removed as partof a balancing process to thereby form a balance cut 549. Such a balancecut can be utilized to help balance a system such as, for example, thesystem 200 of FIG. 2.

As shown, the balance cut 549 is on the sacrificial portion 556 of thethrust collar 540, which does not interfere with the notches 545-1 and545-2. FIG. 11 also shows the thrust collar 540 as including sealelements 555-1 and 555-2 seated in the annular grooves 547-1 and 547-2.In the example of FIG. 11, the compressor wheel side of the thrustcollar 540 is on the left (shown without the backplate 242) while thesleeve side of the thrust collar 540 is on the right (see, e.g., FIG.3). The sensor surface 558 is shown along with the surface 559intermediate the sensor surface 558 and the end 544.

Referring to FIG. 3, the axial length of the rotating group includingthe compressor wheel 250 and the turbine wheel 270 is approximately fourtimes the maximum diameter of the compressor wheel 250. For example,consider a maximum compressor wheel diameter of approximately 90 mm andan end-to-end length of a rotating group of approximately 370 mm. As anexample, a long rotating group may be approximately three times themaximum diameter of a compressor wheel. As an example, an electric motormay have a length of approximately 100 mm. For example, in FIG. 3, theelectric motor assembly 300 may be about 110 mm in length.

As an example, an electric motor can be rated with a power rating. Forexample, consider a power rating of approximately 5 kW to approximately100 kW. As an example, the electric motor assembly 300 can have anelectric motor rated at about 35 kW. As an example, the electric motorassembly 300 may be rated to achieve a maximum revolutions per minute ofapproximately 50,000 rpm or more, 100,000 rpm or more, etc. As anexample, the electric motor assembly 300 may be rated to achieve morethan 100,000 rpm during operation.

The overall axial length of the rotating group of the electric assistsystem 200 tends to be longer than that of a turbocharger with a centerhousing that is a bearing housing without an electric motor. As such,the longer axial length can make balancing, whether static or dynamic,more challenging when compared to a turbocharger without an electricmotor disposed between a compressor wheel and a turbine wheel. Thethrust collar 540 with its sacrificial portion 566 being positionedrelatively close to the compressor wheel 250 can provide for balancingin addition to one or more other components that can provide forbalancing of the rotating group of the system 200.

As to balancing, turbo machinery parts are balanced in an effort to keepthe center of gravity along a rotating axis. When balancing thesubassemblies of a rotating group, many of the components tend to besubstantially cylindrical. Balancing can involve removal of material,for example, through a process such as grinding. Removing material thatis radially close the rotating axis tends to have relatively littleeffect to correct balance. As explained above, the thrust collar 540includes a sacrificial portion 556, which may be more than one portion,which provides a substantially triangular cross-section of material thatis far enough away, radially, from the rotating axis to such thatremoval of material therefrom can effectuate an improvement in balance.Where a speed sensor is utilized, a sacrificial portion may be notched,which may form sacrificial portions (e.g., that span arc lengths). Wherea speed sensor is utilized, a sacrificial portion or portions may bepositioned to be away from a tip of the speed sensor.

As an example, a balancing process can include balancing a subassemblyof a system such as the system 200. In such an example, subassemblyunbalance may be calculated through a physical measurement. As anexample, the thrust collar 540 can have material removed in a specifiedamount per calculations at a specified angle about a rotating axis. Asan example, the thrust collar 540 may be cut before and/or afterinstallation as part of a rotating group. For example, an unbalancemeasurement tool may measure unbalance and a calculation may be made(e.g., via hand and/or by computer, circuitry, etc.) that indicates anamount of material (e.g., a mass) to be removed from a sacrificialportion of a thrust collar. The material may then be removed from thesacrificial portion of the thrust collar and the thrust collar installedon a shaft between a shaft sleeve and a compressor wheel. The assemblymay be measured again as to unbalance and further adjustments made, asdesired. For example, one or more additional cuts may be made to athrust collar and/or one or more other components.

As an example, a turbocharger, whether with electric motor assist orwithout electric motor assist, may be mounted with respect to aninternal combustion engine where a shaft of the turbocharger issubstantially horizontal or where the shaft of the turbocharger deviatesfrom being substantially horizontal. For example, consider aturbocharger that is mounted where its shaft is at an angle of aboutplus or minus three degrees to about plus or minus 10 degrees fromhorizontal (e.g., 0 degrees, which may be defined with reference togravity), where a turbine side may be down (plus) or up (minus). In suchan example, the turbocharger may be mounted with a slope where gravitycan affect mechanical and/or fluid behaviors. For example, as tomechanical behaviors, balance may be affected and, as to fluidbehaviors, flow of lubricant may be affected.

As an example, consider a turbocharger that has a 5 degree slope, withrespect to the rotating axis, with the turbine side down once installedin a vehicle. As mentioned, such a slope can affect balance andlubricant behaviors. Where the turbocharger is a long turbocharger(e.g., about three times to four times compressor wheel maximum diameteror more in axial length), such as for an electric motor assistturbocharger, an ability to balance subassemblies of a rotating groupcan be desirable.

As an example, a turbocharger can include a turbine side collar thatincludes a ramped portion that can help to sling lubricant to walls thatdefine an interior chamber of a housing such that the lubricant canbetter collect at a lubricant drain. Such a turbine side collar can helpto reduce an amount of lubricant that may otherwise have a tendency toescape into a turbine stage, for example, for a given installationslope. As mentioned, turbo machinery parts have to be balanced to keepthe center of gravity along a rotating axis. When balancing thesubassemblies of a rotating group, many components are cylindrical. Tohelp balance, material can be removed, through a process such as, forexample, grinding. Removing material that is radially close to therotating axis tends to have relatively little effect to correct balance.As an example, a turbine side collar can provide material that is farenough away, radially, from the rotating axis such that removal of aportion of such material can make a balance improvement.

As mentioned, unbalance may be calculated and/or measured, for example,via an unbalance measurement tool (e.g., a machine, etc.). As anexample, a turbine side collar can have material removed in a specifiedamount and, for example, at a particular angle about a longitudinal axisof the collar or without regard to angle. As an example, a cut turbineside collar may be installed in an angular orientation that allows atleast a portion of the unbalance to be corrected. As an example, abalancing process or balancing processes may include cutting thecompressor wheel 250 and/or the nut 258 and/or the thrust collar 540and/or a turbine side balance collar (see, e.g., FIGS. 12, 13 and 14).

FIG. 12 shows an example of a balance collar 1240 that may be utilizedon a turbine side of the system 200. As shown, the balance collar 1240includes a stepped bore 1241 that extends between opposing ends 1242 and1244 where a shoulder contour 1245 has a flared shape that matches anexterior surface of the balance collar 1240. As shown, the balancecollar 1240 includes a perimeter 1243, which is at a maximum diameter ormaximum radius of the balance collar 1240. As shown, the balance collar1240 can include a sloped annular end surface 1247 where the slope isradially inwardly over an axial distance from the perimeter 1243 towardthe end 1244, which corresponds to a turbine end of the balance collar1240 (e.g., the end 1242 may be a compressor end of the balance collar1240 or an electric motor and/or electric generator end of the balancecollar 1240). As shown in the example of FIG. 12, the sloped annular endsurface 1247 extends from the perimeter 1243 at the radius r₃ to an edgeat a radius r_(e) over the axial distance z₄, which may define an angleϕ.

In the example of FIG. 12, the balance collar 1240 includes a stemportion 1252 and a flared portion 1254 that includes a sacrificialportion 1256.

FIG. 12 shows various dimensions as may be given with respect to acylindrical coordinate system, including radii r₁, r₂, r₃ and axiallengths z₁, z₂, z₃ and z₄. As shown, the stepped bore 1241 includes aradius r₁ over an axial length of about z₂, noting that an annularchamfer can exist at an outer end of the bore 1241 at the end 1242. Overan axial length z₃, the stepped bore 1241 forms an annular axial face1246 that can be substantially planar in an r,Θ-plane at an axial zposition. The stepped bore 1241 then has the shoulder contour 1245 as asurface that extends to the end 1244.

As shown in the example of FIG. 12, the stem portion 1252 extendsbetween the end 1242 and the annular axial face 1246 and may act as anaxially locating portion of the balance collar 1240. For example, thestem portion 1252 may be part of an axial stack up of a rotating groupwhere the balance collar 1240 rotates with the rotating group due toaxial force applied to the stem portion 1252. As an example, the end1242 may be in contact with the shaft sleeve 450 and the annular axialface 1246 may be in contact with another component such as a seal collarand/or a hub portion of a shaft (e.g., the hub portion 430 of the shaft400).

The sacrificial portion 1256 can be a substantially annular ring portionthat may be defined by an axial dimension z₄ between radii r_(s) and r₃.The sacrificial portion 1256 may be cut to remove at least some of itsmaterial to effectuate a balance cut according to an unbalancemeasurement and/or unbalance calculation. As an example, a cut may be astraight cut that forms a flat, as may be defined by a chord of acircle. A chord of a circle is a straight line segment whose endpointsboth lie on the circle. In such an example, the circle can be theperimeter 1243 of the balance collar 1240.

FIG. 13 shows the balance collar 1240 as including a balance cut 1249,which is shown approximately as a flat portion at the perimeter 1243,which may be defined at least in part by a chord of a circle. Such abalance cut can be utilized to help balance a system such as, forexample, the system 200 of FIG. 2.

FIG. 14 shows examples of a portion of a turbine side of a system 1400and a system 1401 where each includes the shaft 400, the shaft sleeve450, the turbine wheel 270, the cartridge 810, the bearing assemblies820 and 830 and the outer lock nut 870 and where the system 1401includes the lock nut 850.

As shown in the example system 1400 of FIG. 14, the balance collar 1240can be positioned with the end 1242 against the end of the shaft sleeve450 and the end of the inner race of the bearing assembly 820 and withthe annular axial face 1246 of the balance collar 1240 against thesurface 432 of the hub portion 430 of the shaft 400 where the hubportion 430 can include one or more annular grooves 445 that can seatone or more seal elements such as, for example, one or more pistonrings, which may contact an inner bore surface of a housing and/or aplate (see, e.g., the plate 262 of the system 200 of FIG. 2). As shown,the balance collar 1240 is stacked with the rotating group over theaxial length z₂. Thus, the balance collar 1240 may be utilized toaxially locate an inner race of a bearing assembly, optionally without alock nut such as the lock nut 850.

As shown in the example system 1401 of FIG. 14, the balance collar 1240can be positioned between the end of the shaft sleeve 450 and the axialface surface 432 of the hub portion 430 of the shaft 400 where the hubportion 430 can include one or more annular grooves 445 that can seatone or more seal elements such as, for example, one or more pistonrings, which may contact an inner bore surface of a housing and/or aplate (see, e.g., the plate 262 of the system 200 of FIG. 2). As shown,the balance collar 1240 is stacked with the rotating group over theaxial length z₂ (see, e.g., FIG. 12).

As shown in the example system 1400 of FIG. 14, the hub portion 430proximate to the end 454 of the shaft sleeve 450 is not in contact withthe end 454 of the shaft sleeve 450, rather, axial force applied to theshaft sleeve 450 (e.g., via tightening of the nut 258 on to the shaft400) is transferred to the hub portion 430 of the shaft 400, which is ashaft and turbine wheel assembly (SWA).

In the example system 1401 of FIG. 14, the end 454 of the shaft sleeve450 is in contact with the end 1242 of the balance collar 1240 and theannular axial face 1246 of the balance collar 1240 is in contact withthe axial face surface 432 of the hub portion 430 of the shaft 400,which is a shaft and turbine wheel assembly (SWA). As shown in theexample system 1401 of FIG. 14, axial force applied to the shaft sleeve450 (e.g., via tightening of the nut 258 on to the shaft 400) istransferred to the axial face surface 432 of the hub portion 430 of theshaft 400, which is shown as being attached to the turbine wheel 270.

FIG. 14 shows arrows that approximate directions of flow of lubricant tothe bearing assemblies 820 and 830 where lubricant may flow axiallyoutwardly between an annular gap or gaps between the lock nut 850 andthe outer lock nut 870 toward the balance collar 1240. Lubricant canthen contact the outer surface of the balance collar 1240 and migrateaxially toward the turbine wheel 270 and radially outwardly toward theperimeter 1243 of the balance collar 1240, which may include one or morebalance cuts. Lubricant can be flung substantially radially outwardlyaway from the balance collar 1240 as it rotates such that lubricant canmore readily flow toward a lubricant exit with reduced risk of lubricantmigrating toward the seal mechanism that acts to seal a turbine spacewith exhaust gas from a bearing space with lubricant.

As an example, a stem portion of a balance collar can bear a load. As anexample, a larger diameter balance collar can have a larger effect onbalance when cut. As an example, a cut can be a flat cut, which may helpto avoid stress concentration when compared to, for example, a radialnotch. As an example, a disc cutting tool may be utilized to cut abalance collar. As an example, a balance collar can be installed as partof a rotating group, imbalance measured, the balance collar marked, thebalance collar removed, the balance collar cut and the balance collarinstalled at an appropriate alignment such that the balance collar ascut helps to balance the rotating group. As an example, a cuttingprocess may cut a balance collar in situ where a tool can access thebalance collar as part of a rotating group and where vacuum, a fluidstream, etc., may be utilized to help assure that debris does notinterfere with the rotating group (e.g., bearing assemblies, etc.). Asan example, where a lock nut is utilized, a balance collar may be shapedto allow for line of sight access to a set screw of a lock nut such thatthe set screw may be adjusted without having to remove the balancecollar.

FIGS. 15 and 16 show an example of the locating plate 910 with respectto the compressor side cartridge housing 290 along with a view of therecess 613 of the cartridge 610 and an example of the locating plate 930with respect to the center housing 280 along with a view of the recess813 of the cartridge 810. As shown, the locating plate 910 can includeone or more openings 915-1 and 915-2 and the locating plate 930 caninclude one or more openings 935-1 and 935-2. Such opening or openingsmay be utilized to bolt the locating plate 910 or the locating plate 930to a housing.

In FIGS. 15 and 16, an arrow is shown, labeled G, as representing anapproximate direction of gravity (e.g., as the system 200 may be locatedand mounted in a vehicle's engine compartment). FIG. 15 shows alubricant drain passage as being downwardly located with respect togravity and FIG. 16 shows a lubricant drain passage as being downwardlylocated with respect to gravity.

The locating plate 910 and/or the locating plate 930 may be utilized ina system to provide for anti-rotation and/or axial retention. Forexample, such an approach may be utilized where a threaded pin in abearing or plate on an end of a bearing cannot be used, which may be thecase in some types of electric motor assist turbochargers.

As shown in FIG. 9, the locating plate 910 includes the extension 913that extends radially inwardly and the locating plate 930 includes theextension 933 that extends radially inwardly.

As shown in FIGS. 15 and 16, an extension (e.g., a tooth or key) canextend from a plate to stop (e.g., limit) rotation of a cartridge thatincludes one or more bearing assemblies. As mentioned, when an extensionis inserted into a closed recess (e.g., a closed slot), the extensioncan also stop (e.g., limit) axial movement.

As an example, a plate and a recess may be dimensioned to limit rotationabout an axis to a limited number of degrees and may be dimensioned tolimit axial movement to a limited distance.

As an example, a plate and a recess may allow for some amount of radialmovement. For example, the extension 913 of the locating plate 910 canbe received by the recess 613 of the cartridge 610 where some radialmovement of the cartridge 610 may occur, for example, within limits thatmay be defined by the seal elements 663 and 665, which may beelastomeric seal elements that can deform to some extent (see also FIG.4). Such deformation may be elastic deformation such that theelastomeric seal elements can return to an original shape. As anexample, a rotating group can move radially within some amount oftolerance as may be determined by various seal elements.

As an example, the extension 933 of the locating plate 930 can bereceived by the recess 813 of the cartridge 810 where some radialmovement of the cartridge 810 may occur, for example, within limits thatmay be defined by the seal elements 863 and 865, which may beelastomeric seal elements that can deform to some extent (see also FIG.4). Such deformation may be elastic deformation such that theelastomeric seal elements can return to an original shape. As anexample, a rotating group can move radially within some amount oftolerance as may be determined by various seal elements.

As an example, the recess 813 of the cartridge 810 can include flatportions and notched corners. FIG. 16 shows a plan view of the recess813 with the extension 933 received therein where the recess 813 isrectangular shaped in the plan view (e.g., noting that the recess 813 isarced about the z-axis) where the corners of the recess 813 are notched,for example, via drilling. In such an example, corners of the extension933 may be non-contact corners in that they cannot contact a surface ofthe cartridge 810 because the corners of the recess 813 are notched. Forexample, where the cartridge 810 moves azimuthally about the z-axis(e.g., in an angular direction Θ of a cylindrical coordinate systemabout the z-axis), a flat surface of the extension 933 (e.g., a sideedge surface) and a flat surface of the recess 813 (e.g., a side wallsurface) can contact as the corner notches provide space to receive thecorners of the extension 933. Where movement occurs in an axialdirection along the z-axis as to the cartridge 810, a flat surface ofthe extension 933 (e.g., a face surface) and a flat surface of therecess 813 (e.g., a facing wall surface) can contact as the cornernotches provide space to receive the corners of the extension 933. As anexample, the corner notches may be formed via drilling with a rotatingdrill bit and may be formed prior to cutting the recess 813 into thecartridge 810. In the example of FIG. 16, the corner notches may reducestress and/or wear during operation of a system such as the system 200of FIG. 2.

As an example, a system can include a plate as in FIG. 15 and/or a plateas in FIG. 16. As an example, a system can include a cartridge with arecess and without a plate with an extension. As an example, a systemcan include a compressor side bearing assembly in a compressor sidecartridge and a turbine side bearing assembly in a turbine sidecartridge. In such an example, a compressor side locating plate can beutilized to limit rotation and/or axial movement of the compressor sidecartridge and/or a turbine side locating plate can be utilized to limitrotation and/or axial movement of the turbine side cartridge. In such anapproach, radial movement of the compressor side cartridge and/or theturbine side cartridge may be allowed in a radial direction, which maybe a direction substantially aligned with gravity. Such radial movementmay be limited by one or more lubricant squeeze films and/or one or moreelastomeric (e.g., spring or spring-like) members.

As an example, two plates may provide for limiting azimuthal rotation oftwo independent cartridges that include bores that receive ball bearingassemblies. In such an example, the two plates may work cooperatively tolimit axial movement of the two independent cartridges, one plate in oneaxial direction and the other plate in another, opposing axialdirection. As shown in FIG. 16, a plate and a recess may act to limitaxial movement of an assembly that includes a compressor side cartridgeand a turbine side cartridge. As an example, a turbine side plate withan extension and a turbine side cartridge with a recess that receivesthe extension may be dimensioned to account for thermal effects (e.g.,thermal expansion, etc.). As an example, as to a compressor side of asystem, temperature and temperature range may be less than at a turbineside of the system, particularly where an electric motor assembly may bedisposed between the turbine side and the compressor side of the system.

As an example, a system may be a fuel cell system that includes twocompressor wheels that can be disposed on a common shaft, which may be aunitary shaft or a shaft assembly. Such an approach can include a motordriven by the fuel cell. As an example, one or more features describedherein may be included in a fuel cell system that includes one or morecompressor wheels.

As an example, a cartridge may be made of steel. For example, thecartridge 610 and/or the cartridge 810 may be made of steel. As anexample, a plate or plates may be made of steel. For example, the plate910 and the plate 930 may be made of steel. As an example, a componentmay be made of a metal, a metal alloy or another type of material. As anexample, materials of construction may be selected based in part onoperational temperature or temperatures. As an example, the sleeve 450may be a unitary piece or may be a multi-piece sleeve.

A turbocharger assembly can include a shaft sleeve that includes a borethat extends between a compressor end and a turbine end, outer threadsthat extend to a first axial position from the compressor end, and anouter shoulder at a second, greater axial position from the compressorend; a lock nut that includes inner threads that mate with the outerthreads of the shaft sleeve and an axial length that is less than adistance between the compressor end and the first axial position; and abearing assembly that includes at least one inner race axially locatedby the outer shoulder of the shaft sleeve and axially located by thelock nut.

As an example, a lock nut can include a set screw that is rotatable tocontact the outer threads of a shaft sleeve. As an example, a bearingassembly can include a first inner race, a second inner race and aninner ring disposed axially between the first inner race and the secondinner race.

As an example, a turbocharger assembly can include a shaft received in abore of a shaft sleeve, which can be a through bore that extend from oneend of the shaft sleeve to an opposing end of the shaft sleeve. In suchan example, the turbocharger assembly can include a thrust collar and acompressor wheel disposed on the shaft where the thrust collar isdisposed between the compressor wheel and the shaft sleeve. In such anexample, the thrust collar is located by another outer shoulder of theshaft sleeve where, for example, an axial clearance can exist betweenthe lock nut and the thrust collar such that the thrust collar does notcontact the lock nut. Such an approach can allow for locating a bearingassembly without the bearing assembly carrying an axial load associatedwith fitting a compressor wheel where a fitting load may be carried bythe thrust collar and the shaft sleeve, which may contact a hub portionof a shaft at or near, for example, a turbine end of the shaft sleeve.

As an example, an assembly can include a cartridge that includes a borewhere a bearing assembly is received in the bore of the cartridge. Insuch an example, the assembly can include an outer lock nut thatincludes outer threads where the bore of the cartridge includes innerthreads that mate with the outer threads of the outer lock nut. In suchan example, the outer lock nut can have an axial length that is lessthan the axial length of another lock nut, which can be an inner locknut that threads onto a sleeve to axially locate a bearing assemblyreceived in the bore of the cartridge.

As an example, a bearing assembly or bearing assemblies can include atleast one angular contact ball bearing. As an example, two rollingelement bearing assemblies, each with an inner race, an outer race androlling elements disposed between the inner and outer races, can beoriented in one or more configurations. For example, consider an O-typeconfiguration or an X-type configuration.

As an example, an assembly can include a shaft sleeve that includes anelectric motor rotor. Such an assembly may be a compressor assembly, adual-compressor wheel assembly, a turbine assembly (e.g., with agenerator rotor), a turbocharger assembly, etc. As an example, anassembly may be an electric turbocharger that can operate via electricalpower and/or exhaust gas from an internal combustion engine. As anexample, an electric motor stator can be included in an assembly thatdrives an electric motor rotor.

As an example, an assembly can include a shaft received by a shaftsleeve where the shaft includes a hub portion and where a turbine end ofthe shaft sleeve contacts the hub portion. In such an example, theassembly can include a compressor wheel disposed on the shaft, a thrustcollar disposed on the shaft and a nut disposed on the shaft where thenut applies a load to the compressor wheel, the thrust collar and theshaft sleeve between the nut and the hub portion of the shaft. In suchan example, a bearing assembly that rotatably supports a rotating groupthat includes the compressor wheel, the nut, the thrust collar, theshaft and the shaft sleeve can be independent of the applied load to thecompressor wheel, the thrust collar and the shaft sleeve between the nutand the hub portion of the shaft. In such an approach, a race (e.g., aninner race or an outer race) of a bearing assembly can be designed,dimensioned, made of a material of construction, etc., that does notneed to account for the applied load to the compressor wheel. As anexample, a bearing assembly may be loaded independent of an applied loadto a compressor wheel. As an example, a bearing assembly may be axiallylocated in a manner that does not depend on a surface or surfaces of acomponent or components that experience an applied load to a compressorwheel.

As an example, a compressor assembly can include a shaft sleeve thatincludes a bore that extends between a first end and a second end and anouter shoulder; a shaft received by the bore of the shaft sleeve wherethe shaft includes a compressor end; a compressor wheel disposed on theshaft; and a thrust collar disposed on the shaft and seated between theouter shoulder of the shaft sleeve and the compressor wheel where thethrust collar includes a stem portion and a cap portion that includes asacrificial portion. In such an example, the sacrificial portion of thethrust collar can include at least one balance cut. A balance cut can bea deviation in a profile of a sacrificial portion. For example, asacrificial portion can be formed to have a profile that is relativelyconsistent about an azimuthal span or spans about a longitudinal axis ofa thrust collar that includes the sacrificial portion. A balance cut canbe formed via a tool or tools. For example, a drilling tool or cuttingtool may be utilized to remove material from a sacrificial portion suchthat the profile of the sacrificial portion bears indicia of materialremoval. When a thrust collar is considered as part of a rotating group,the shape of the thrust collar, particularly as to the sacrificialportion including at least one balance cut, is a shape that can enhancebalance of the rotating group.

As an example, a cap portion of a thrust collar can include a sensornotch or sensor notches. In such an example, a sensor notch may extendthrough A sacrificial portion of the thrust collar.

As an example, a thrust collar can include an annular groove about anexterior of a stem portion.

As an example, a sacrificial portion of a thrust collar can include atriangular cross-sectional shape (e.g., as part of a profile or todefine a profile of the sacrificial portion). As an example, asacrificial portion can extend to an outermost perimeter of a thrustcollar. In such an example, a vertex of a triangular cross-sectionalshape may be at the outermost perimeter of the thrust collar. As anexample, a sacrificial portion can extend axially to an apex, which maybe, for example, a vertex of a triangular cross-sectional shape of thesacrificial portion.

As an example, an assembly can include a thrust collar that includes aplane disposed at an axial position where a sacrificial portion of thethrust collar is disposed axially to one side of the plane. In such anexample, the sacrificial portion can be disposed axially to the side ofthe plane that is toward a compressor end of the shaft.

As an example, a balance cut in a sacrificial portion of a thrust collarcan be inset radially from an outermost perimeter of a cap portion ofthe thrust collar.

As an example, a compressor assembly can include a speed sensor. As anexample, a compressor assembly can include a shaft sleeve that isoperatively coupled to a rotor of an electric motor. In such an example,a stator may be energized to cause the rotor to rotate and, for example,rotate a compressor wheel disposed in a compressor housing that includesa diffuser section and a volute with an opening for compressed air(e.g., air, air and exhaust, etc.).

As an example, a method can include measuring unbalance of a rotatinggroup of a turbocharger; and, based at least in part on the unbalance,removing an amount of material from a sacrificial portion of a thrustcollar. In such an example, the thrust collar can include a stem portionwith a through bore and a cap portion where the sacrificial portionextends from the cap portion. As an example, the aforementioned methodcan include rotating the rotating group via an electric motoroperatively coupled to the turbocharger (e.g., energizing an electricmotor to rotate the rotating group via an electric motor rotor fit to ashaft of the turbocharger). As an example, a turbocharger can include anelectric motor where the electric motor is disposed between a compressorwheel and a turbine wheel of the turbocharger.

As an example, a turbocharger assembly can include a shaft sleeve thatincludes a bore that extends between a first end and a second end; ashaft received by the bore of the shaft sleeve where the shaft includesa compressor end and a turbine wheel that defines a turbine end; and abalance collar disposed on the shaft and seated axially between the endof the shaft sleeve and the turbine wheel where the balance collarincludes a stem portion and a flared portion that includes a sacrificialportion. In such an example, the sacrificial portion of the balancecollar can include at least one balance cut. A balance cut can be adeviation in a profile of a sacrificial portion. For example, asacrificial portion can be formed to have a profile that is relativelyconsistent about an azimuthal span or spans about a longitudinal axis ofa balance collar that includes the sacrificial portion. A balance cutcan be formed via a tool or tools. For example, a drilling tool orcutting tool may be utilized to remove material from a sacrificialportion such that the profile of the sacrificial portion bears indiciaof material removal. When a balance collar is considered as part of arotating group, the shape of the balance collar, particularly as to thesacrificial portion including at least one balance cut, is a shape thatcan enhance balance of the rotating group.

As an example, a balance collar can include a balance cut defined atleast in part by a chord of a circle where the circle has a radiusdefined by an outermost perimeter of the balance collar. In such anexample, a cutting tool, which may be a rotating disk cutting tool, mayremove a portion of the balance collar to form the balance cut.

As an example, a balance collar can include a stepped bore that includesan annular axial face. In such an example, an axial face surface of ahub portion of a shaft can be utilized to seat against the annular axialface. As an example, a balance collar can be loaded between an end of acomponent and a hub portion of a shaft. As an example, in a turbochargerassembly, a balance collar can be loaded by an axial load between an endof a shaft sleeve and an axial face surface of a hub portion of a shaftthat is disposed at least in part in a bore of the shaft sleeve. In suchan example, the shaft can have a turbine wheel welded thereto and canhave a compressor wheel fit thereto. For example, consider a compressorwheel with a through bore where a portion of the shaft is received bythe through bore of the compressor wheel and where a nut may be threadedonto threads of the shaft to apply a load to the compressor wheel, whichmay be, for example, carried by the shaft sleeve and the hub portion ofthe shaft with one or more components disposed along an axial stack-upchain.

As an example, a sacrificial portion of a balance collar can be disposedover an axial length of the balance collar that does not overlap axiallywith a stem portion of the balance collar. For example, a stem portionof a balance collar can be axially offset from a sacrificial portion ofthe balance collar. Such an approach may help to decouple stress(es)experienced by the sacrificial portion from effecting the stem portion,which may, for example, carry an axial load (e.g., as part of an axialstack-up chain of a rotating group).

As an example, a sacrificial portion of a balance collar can be disposedat a radial distance greater than an outermost radius of a stem portionof the balance collar. As an example, a sacrificial portion of a balancecollar can include a sloped annular end surface, which may be shape tosling lubricant (e.g., oil, etc.) while the balance collar is rotatingabout a longitudinal axis in unison with a rotating group.

As an example, a turbocharger assembly can include a balance collar anda shaft sleeve that is operatively coupled to a rotor of an electricmotor. In such an example, the balance collar can include a balance cutor cuts that enhance the balance of the turbocharger, as driven by theelectric motor and/or by exhaust gas that flows through a turbinehousing to rotatably drive a turbine wheel.

As an example, a method can include measuring unbalance of a rotatinggroup of a turbocharger; and, based at least in part on the unbalance,removing an amount of material from a sacrificial portion of a turbineside balance collar. In such an example, the balance collar can includea stem portion with a through bore where the sacrificial portion isaxially offset from the stem portion. For example, a balance collar canhave an axial length where the stem portion has an axial length over anaxial span and where the sacrificial portion has an axial length over anaxial span where the axial spans do not overlap axially. In such anexample, the balance collar can include a stepped through bore where anannular face within the stepped through bore can be utilized to seat acomponent where a load may be transferred from the balance collar to thecomponent. In such an example, a shaft sleeve may apply a load to thebalance collar and the balance collar may transfer that load to thecomponent, which may be a hub portion of a shaft that is received atleast in part by a through bore of the shaft sleeve.

As an example, a method can include rotating a rotating group via anelectric motor operatively coupled to a turbocharger as part of abalancing process. In such an example, the turbocharger can include theelectric motor where the electric motor is disposed between a compressorwheel and a turbine wheel of the turbocharger.

As an example, a system can include a housing that includes a borehaving a longitudinal axis; a cartridge disposed in the bore where thecartridge includes a recess; a bearing assembly disposed in thecartridge where the bearing assembly includes an outer race and rollingelements; and a locating plate attached to the housing where thelocating plate includes an extension that is received by the recess ofthe cartridge. In such an example, the cartridge can include the recessas a keyway and the locating plate can include the extension as a keywhere the key can be received at least in part by the keyway.

As an example, a cartridge can be a compressor side cartridge where arecess is an open recess and where an extension of a locating platelimits rotation of the cartridge about a longitudinal axis. In such anexample, an open recess can be a recess with an open side, for example,it can be a three-sided recess where an open side is an axial side.

As an example, a cartridge can be a turbine side cartridge where arecess includes a closed recess where an extension of a locating platelimits rotation of the cartridge about a longitudinal axis and limitsaxial movement of the cartridge along the longitudinal axis. In such anexample, a closed recess can be a recess without an open side, forexample, it can be a four sided recess. As an example, such a recess mayinclude one or more notched corners such that one or more corners of theextension of the locating plate does not or do not directly contact awall of the recess (e.g., material of the cartridge). Such an approachcan reduce wear as to the extension and/or the cartridge.

As an example, a recess can be a keyway and an extension can be a key.As an example, a system can include a key and keyway pair or pairs. Asan example, a cartridge may include a key and another component mayinclude a keyway (e.g., a housing, a component attached to a housing,etc.).

As an example, an extension can be received by a recess of a cartridgein a manner that allows for radial movement of the cartridge withrespect to the longitudinal axis. In such an example, the radialmovement may be in a direction that is substantially aligned withgravity (e.g., as a system may be mounted in a vehicle that is flat on ahorizontal surface).

As an example, a system can include a seal element disposed between acartridge and a bore of a housing. In such an example, deformation ofthe seal element can provide for radial movement of the cartridge withrespect to a longitudinal axis of the bore of the housing. As anexample, a seal element can be an elastomeric seal element, which may beat least in part elastomeric (e.g., consider a composite element).

As an example, a cartridge can include a lubricant inlet where, forexample, seal elements disposed between a bore of a housing and thecartridge can define a lubricant space where the lubricant inlet isdisposed axially between the seal elements.

As an example, a system can include an electric motor. As an example, asystem may be a compressor system, a turbine system, a turbochargersystem, etc. As an example, a system can include one or more compressors(e.g., consider a system with a compressor at one end, an electric motorand another compressor at another end).

As an example, a system can include a shaft sleeve where a bearingassembly is mounted to the shaft sleeve and where the bearing assemblyis disposed at least in part in a bore of a cartridge, which may belocated axially and/or azimuthally by a key and keyway pair. In such anexample, the system can include an electric motor rotor that is mountedto the shaft sleeve.

As an example, a system can include a housing assembly that includes acompressor side bore and a turbine side bore having a commonlongitudinal axis; a compressor side cartridge disposed in thecompressor side bore where the compressor side cartridge includes arecess; a compressor side locating plate attached to the housingassembly where the compressor side locating plate includes an extensionthat is received by the recess of the compressor side cartridge; aturbine side cartridge disposed in the turbine side bore where theturbine side cartridge includes a recess; and a turbine side locatingplate attached to the housing assembly where the turbine side locatingplate includes an extension that is received by the recess of theturbine side cartridge. In such an example, the recess of the compressorside cartridge can be an open recess and the extension of the compressorside locating plate can limit rotation of the compressor side cartridgeabout the longitudinal axis and/or the recess of the turbine sidecartridge can be a closed recess where the extension of the turbine sidelocating plate limits rotation of the turbine side cartridge about thelongitudinal axis and limits axial movement of the turbine sidecartridge along the longitudinal axis and, optionally where, thelimitation of axial movement of the turbine side cartridge along thelongitudinal axis also limits axial movement of the compressor sidecartridge along the longitudinal axis.

As an example, a system can include extensions received by recesses ofcartridges that allow for radial movement of cartridges with respect toa longitudinal axis of a rotating group of the system.

As an example, a system can include an electric motor. As an example, anelectric motor can include a rotor operatively coupled to a shaft,optionally via a shaft sleeve. Such a system can include a compressor,compressors, a turbine, turbines, etc.

As an example, a system can include a shaft sleeve, a compressor sidebearing assembly disposed in a compressor side cartridge and mounted tothe shaft sleeve and a turbine side bearing assembly disposed in aturbine side cartridge and mounted to the shaft sleeve. In such anexample, the system can include an electric motor rotor that is mountedto the shaft sleeve.

Although some examples of methods, devices, systems, arrangements, etc.,have been illustrated in the accompanying Drawings and described in theforegoing Detailed Description, it will be understood that the exampleembodiments disclosed are not limiting, but are capable of numerousrearrangements, modifications and substitutions.

What is claimed is:
 1. A compressor assembly comprising: a shaft sleevethat comprises a bore that extends between a first end and a second endand that comprises an outer shoulder; a shaft received by the bore ofthe shaft sleeve wherein the shaft comprises a compressor end; acompressor wheel disposed on the shaft; and a thrust collar disposed onthe shaft and seated between the outer shoulder of the shaft sleeve andthe compressor wheel wherein the thrust collar comprises a stem portionand a cap portion that comprises a sacrificial portion, wherein the capportion comprises a sensor surface, wherein the sacrificial portion ison a compressor wheel side of the thrust collar and the sensor surfaceis on a shaft sleeve side of the thrust collar, wherein the sacrificialportion of the thrust collar comprises at least one balance cut, andwherein the cap portion of the thrust collar comprises a sensor notchthat forms a notch in the sensor surface and extends through thesacrificial portion.
 2. The compressor assembly of claim 1 wherein thethrust collar comprises an annular groove about an exterior of the stemportion.
 3. The compressor assembly of claim 1 wherein the sacrificialportion comprises a triangular cross-sectional shape.
 4. The compressorassembly of claim 1 wherein the sacrificial portion extends to anoutermost perimeter of the thrust collar.
 5. The compressor assembly ofclaim 1 wherein the sacrificial portion extends axially to an apex. 6.The compressor assembly of claim 1 comprising a plane disposed at anaxial position wherein the sacrificial portion is disposed axially toone side of the plane, wherein the sacrificial portion is disposedaxially to the side of the plane that is toward the compressor end ofthe shaft.
 7. The compressor assembly of claim 1 wherein the balance cutis inset radially from an outermost perimeter of the cap portion of thethrust collar.
 8. The compressor assembly of claim 1 comprising a speedsensor wherein the speed sensor is on the shaft sleeve side of thethrust collar.
 9. The compressor assembly of claim 1 wherein the shaftsleeve is operatively coupled to a rotor of an electric motor.
 10. Amethod comprising: providing a rotating group of a turbocharger thatcomprises a compressor assembly that comprises a shaft sleeve thatcomprises a bore that extends between a first end and a second end andthat comprises an outer shoulder, a shaft received by the bore of theshaft sleeve wherein the shaft comprises a compressor end, a compressorwheel disposed on the shaft, and a thrust collar disposed on the shaftand seated between the outer shoulder of the shaft sleeve and thecompressor wheel wherein the thrust collar comprises a stem portion anda cap portion that comprises a sacrificial portion, wherein the capportion comprises a sensor surface, wherein the sacrificial portion ison a compressor wheel side of the thrust collar and the sensor surfaceis on a shaft sleeve side of the thrust collar, and wherein the capportion of the thrust collar comprises a sensor notch that forms a notchin the sensor surface and extends through the sacrificial portion;measuring unbalance of the rotating group of the turbocharger; and basedat least in part on the unbalance, removing an amount of material fromthe sacrificial portion of the thrust collar to form at least onebalance cut.
 11. The method of claim 10 comprising rotating the rotatinggroup via an electric motor operatively coupled to the turbocharger. 12.The method of claim 11 wherein the turbocharger comprises the electricmotor wherein the electric motor is disposed between the compressorwheel and a turbine wheel of the turbocharger.